Resultant-tilt finder



Nov. 15,1927. 1,649,406

L. J. R. HoLsT RESULTANT TILT FINDER Original Filed Sept. 1. 1925 ZSheetS-Sheet 1 Nov. 15, 1927. 1,649,406

L. J. R. HOLST REsULTANT TILT FINDER original Filed sept. 1. l1925 2 sheets-Sheet 2 endSIOfthearmsw 55' protractor K formed on the of the vPatented Nov. 15, 1927.

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OF BROOKLINE, IPENNSYLVAN'IA,v ASSIGNOR T0 BROCK 66 WEY- MOUTH, INCORPORATED, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATIION 0F DELAWARE.

nEsULTAN'r-TILT FINDER.

Application mea september 1, i925, sei-iai No. 53,778. Renewed october s, i927.

In Patent Number 1,565,413 of Arthur Brock, Jr. `and Lodewyk R. Holst, Dec. 15, 1925, a method of making maps from a series of overlapping photographs is described, which involves a determination of the tilt from a horizontal plane of .the photographic plates with reference to two axes, one corresponding to the line of ight or" the aeroplane from` which the photolo graphs are taken and the other corresponding to a line at right angles to the first axis and passing through the center point of the plate. From the data thus obtained the true axis of tilt and the magnitude of l5 theangle of tilt can be determined, ,and the plates reprojected to provide plates corre- M sponding to a horizontal pro]e ction.

The object loit my invention is to provide a machine by the use of which" the true axis A and angle of tilt'can be easily and promptly determined.

The nature of my invention will be best understoodgas described in connectionl with the drawings, which illustrate 'a machine em Z5 bodyingmy invention, and in which.

Figure 1 is a plan'view of the machine; Figure 2 a front elevation; l Figure 3 a vertical section on line 3--3 of Figure 1; and

Figures t and---5 are diagrammatic 'views of a stereoscopic pair-of photographicplatesarranged so that the line correspondirirgr to the line of flight. of the aeroplane o m which they were taken passes through 'the 35 center and conjugate center points ofboth in the gimbal ring to the angle of tilt deterplates.

, A is the base plate provided with levelling screws A1; standards A2, A2; a segmental guideway A1 having 'an undercut slot A1 and 40 a pivot pin A5. .i p B and B1 are pivot pins havingV bearings in the standards A2 and secured to a gimbal ring D. E is a platenlclonsttuted oa disk segment of more than 180 and supported by i'neansA of arms E1, E1, pivot pins E1, E, which have their bearings in the ring D ina line running at right angles to the line ofthe pivots B, B1, the two lines in ter secting at the center of the ring.. E is a pivot pin extending on both sidesof the j platen at the center of the gimba'l ring.r F,-

- F1F'"A is a three varmed lever pivoted on pin E? and havin 4verniers. f1 f1 andv f at the g hicii--iegisarv Wahine as one tilt axis and lines y-y passing yangle measured'on the prctractor K. This platen'. G is a spirit' level secured on arm- F which shows level when the platen is in horizontal position. H is an arm pivoted on pin A5 directly below pivot E* and carrying a protractor H1 and a clamping -screwv H2. I is a protractor secured to pivot pin. B1 and registering with a Vernier I1 screwed on standard A2. J is a protractor secured to pivotpin E3 and registering with a Vernier J1 attached to gimbal ring D. La is an arm pivoted on the lower end of pin E4 and carrying a Vernier L1 which registers with protractor H1. Y

In Fig. 41 thepair of plates indicated at (l) and (3) have indicated at C1 and C3 the center points of the views and at c1 and 03, the conjugate center points as they appear on the plates. The flying linel-f-m passing through these points may be taken through the center of each plate and at right angles to line wis the other tilt axis. M and M1 are points in plate (1) lying in orA near axis .ye-y and M2, M3 points in plate (3) lying in or near the tilt axis y-y of that plate. m, m1, m2 an'dm3 are the conjugates of these points asthey appear inthe ,f other plate.

My machine is intended to ascertain the true axis and angle oftilt of the lates after the direction of tilt and angle o tilt of the 'plates on the selected axes :1i-w and y-y havebeen ascertained. To do this the giin- I bal rino` D is tilted to the horizontal lto the angle ozttilt on axis. :nf-m, the platen is tilted mined as existing on the y-y axis. The three armed lever F, F1, F2 is then turned until the spirit level Gr shows level and. thedetermines thetrue axis of tilt and the tilt angle on this-axis is measured on protractor `H by Vernier L1 aftery theprotractor and i vernierhave been swung into alignment with arm F. The-true axis and angle of tilt hav'- 100 ing been thusv ascertained and the'axis indicated on `each plate, the described reprojection of the plates is easily effected.

Havingnow described my invention, what I new and desire toseciire by Lette Patenais: f eans for. the true tilt.

f .a photographic p ate,v the tilt of` comprising in combination a av` tilt at right angles to the tilt of the giinbal,

a protraotor and Vernier for measuring the `tilt of the gimbal from a horizontal plane,

a protractor and Vernier for measuring the tilt of the platen from the plane of the gimbal, means for determining the true axis of tilt of the platen in any position it occupies consistlng of an arm pivoted' on the platen at a point lyin in the line Where Vertical planes passing t rough the tile axis of the gimbaland platen intersect, and carrying a spirit level and a protraotor and Vermer for measuring the tilt on said true axis.

2. Means forascerta'ining the true tilt axis of a `photographie plate the tilt of which on two arbitrarily selected axes is known, comprising in combination a base, a gimbal ring pivotally supported thereon, a platen 20 piVotally supported on the gimbal to tilt at f right angles to the tilt of the gimbal, a protractor and Vernier for measuring the tilt of the gimbal from a horizontal plane, a protractor and Vernier for measuring the tilt 25 of the platen from the plane'of the gimbal, means for determining the true axis of tilt of the platen in any position it occupies, consisting of a arm pivoted on the platen ata point lying in the line Where Vertical planes\30 passing'through the tilt axis of the gimbal and platen intersect, and carrying a spirit leVel, a protraotor and Vernier for measuring the angular deviation of said true axis of tilt from the tilt axis of the platen and a 35 protraetor and Vernier for measuring the tilt on said true axis.

LODEWYK J. R.` HOLST. 

